Synthesis and characterization of 2H-pyrano[3,2-c]coumarin derivatives and their photochromic and redox properties
- 作者：Chin-Neng Huang ; Pei-Yu Kuo ; Chi-Hui Lin ; Ding-Yah Yang
- 关键词：Coumarin ; Flindersine ; Photochromism ; Redox switch
- 刊名：Tetrahedron
- 出版年：2007
- 期刊代码：107_00404020
- 类别：ch
- 出版时间：1 October 2007
- 卷：63
- 期：40
- 页码：10025-10033
- 文件大小：566 K
摘要
A series of 2H-pyrano[3,2-c]chromen-5-one derivatives were synthesized and characterized. Their photochromic and redox properties were investigated by the UV–vis absorption spectroscopy. While compounds with one or two phenyl groups incorporated at the 2-position were present in both ring-opened (5a and 10a) and ring-closed (6a and 11a) forms, the incorporation of an N,N-dimethylamino group on either side of the aromatic ring resulted in formation of the ring-opened (5b and 10b) forms only. The ring-closed forms 13 and 18 with a methyl substituent at the 3-position of the pyran moiety failed to exhibit photochromic behavior. Compound 23 with an N,N-dimethylamino group on the aromatic ring displayed increasing shoulder absorption in the visible region and a distinct change of color upon UV irradiation. The non-fluorescent 10b instantly changed from dark red to colorless, when treated with sodium borohydride. The reduced 28 was blue fluorescent with a quantum yield of 0.46 and could be returned to its original color via DDQ oxidation.